php - 如何摆脱 json_encode() : Invalid UTF-8 sequence in php?

Question

我收到此警告并且 php 返回 null 。

PHP Warning: json_encode(): Invalid UTF-8 sequence in argument in /var/www/rreadyreckoner/get_instruction.php on line 26 {"result":[{"instruction":null}]}

我正在尝试运行这个 php 脚本。

<?php 
include "demo_config.php";
$con = mysqli_connect($server_name,$mysql_user,$mysql_pass,$dbname);
 if(!$con)
 {
         echo "Connection Error".mysqli_connect_error();
 }
 else{
//echo "";
 }

$query ="SELECT instruction FROM `rreadyreckoner` ORDER BY id DESC LIMIT 1;";

$res = mysqli_query($con,$query);
$result = array();
while($row = mysqli_fetch_array($res))
{
                  array_push($result,
                  array('instruction'=>$row[0]));
}
if(!$result)
{
echo "Nothing to display";
}else
{
echo json_encode(array("result"=>$result));
}
mysqli_close($con);
?>

我所做的唯一更改是在将内容插入 mysql 数据库时删除了默认插入的字符并将其替换为任何内容。

$instruction =$_POST["instruction"];
$plainHTML = str_replace(chr(194),"",$instruction);
$sql = "INSERT INTO rreadyreckoner (id, instruction)
VALUES (NULL, '$plainHTML')";

在这样做之前，我得到了适当的回应。任何帮助或建议表示赞赏。谢谢。

Answer 1

只需添加以下内容:

mysqli_set_charset($con, "utf8");

mysql 连接之后。